These habits tire eye muscles. But they won't permanently damage eyesight.

Wear sunglasses that screen 100% of UVA and UVB rays when outdoors during the day.

A lack of vitamin A severe enough to cause night blindness is rare. But any disease or condition that interferes with how the body absorbs vitamin A can affect night vision.

Lawnmowers cause more than 5,000 eye injuries each year, according to Prevent Blindness America. Stones and other objects can shoot out from beneath a mower, bounce off a curb or foundation, and hit the person mowing. A basketball that goes in an unintended direction can fracture an eye socket, scratch a cornea, or cause other eye damage. Household chemical can damage the eyes if the chemicals accidentally splash. Be cautious when opening and using detergents, bleaches, ammonia, and oven and drain cleaners.

Glaucoma, diabetic retinopathy, and some forms of age-related macular degeneration (AMD) can be successfully treated if diagnosed early enough. That's why it is important to have your vision routinely checked by an eye care provider.

In most cases, increased pressure inside the eye causes glaucoma. Unless this pressure is controlled, it can damage the optic nerve and lead to permanent vision loss. People at risk for glaucoma include African Americans older than 40, anyone older than 60, and those with a family history of glaucoma.

Scientists have found a close tie between cataracts and diabetes, using steroids such as prednisone, and aging. Smoking also raises the risk. So does being out in extremely bright sunlight for long periods of time. Fishermen fall into this group.

In AMD, the cells in the central portion of the retina (macula) gradually stop working. This causes a person's central vision to become fuzzier. Eventually AMD makes it impossible to read, drive, or do close-up work. Most people with AMD still have their peripheral vision.

Make sure your diet includes plenty of these, as well as other vegetables and fruits.

A high-dose combination of these supplements lowered the risk for advanced stages by 25%, according to the study. The study was sponsored by the National Eye Institute. Zeaxanthin, a carotenoid found in spinach and greens, also helps. The wet form of AMD, the less common form, can also be treated with laser therapy or medicine. Several medicines that are injected into the eye have been approved to slow or block the growth of new blood vessels in wet AMD, thus preserving sight.